CD Markers

Topic Completed: 1 August 2013

Revised: 20 December 2018, last major update August 2013

Copyright: (c) 2003-2016,, Inc.

PubMed Search: ICOS

Nat Pernick, M.D.
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Cite this page: Pernick N. CD278. website. Accessed June 4th, 2020.
Definition / general
  • Also called ICOS
  • Enhances basic T-cell responses to a foreign antigen, namely proliferation, secretion of lymphokines, upregulation of molecules that mediate cell-cell interaction and effective help for antibody secretion by B-cells
  • Essential both for efficient interaction between T and B-cells and for normal antibody responses to T-cell dependent antigens
  • Plays a critical role in CD40-mediated class switching of immunoglobin isotypes
  • A type I membrane protein
  • Defects cause ICOS deficiency (OMIM 607594), a form of common variable immunodeficiency characterized by recurrent bacterial infections of the respiratory and digestive tracts, but without splenomegaly, autoimmune disease, sarcoid-like granulomas, overt T cell immunodeficiency
  • Present in: activated T cells, tonsillar T cells, fetal and newborn thymic medulla
Additional references
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